Vitamin D deficiency and the associated factors in children with type 1 diabetes mellitus in southern Iran

Proportion of vitamin D deficiency in children/adolescents with type 1 diabetes: a systematic review and meta-analysis

BACKGROUND

The impact of vitamin D on type 1 diabetes has been a controversial topic in public health. Furthermore, significant differences in the proportion of vitamin D have been noted. The purpose of this systematic review was to determine the overall proportion of vitamin D deficiency in children/adolescents with type 1 diabetes (T1D).

METHODS

Based on six electronic databases (PubMed, Web of Science, Embase, Ovid Medline, ProQuest, and Cochrane Library), eligible studies since the databases' inception up to April 2022 were searched. Reference lists were also manually searched to identify additional studies. Overall, studies with statistical information on vitamin D deficiency in children and adolescents with T1D were included, and a random effects model was applied for the meta-analysis. In addition, subgroup and sensitivity analyses were carried out to evaluate heterogeneity, and publication bias was evaluated by using Egger's test.

RESULTS

A total of 45 studies involving 6,995 participants met the inclusion criteria; these included 25 countries covering Africa, Oceania, Europe, North America and Asia. The proportion of vitamin D deficiency in children/adolescents with T1D was 45% (95% confidence interval [CI] 37-54%, I2 = 97.94%). Subgroup analysis further revealed that the publication year, study design, vitamin D classification, season and geographical region significantly contributed to the variation in the reported incidence of vitamin D deficiency.

CONCLUSIONS

The results of the meta-analysis showed that the proportion of vitamin D deficiency among T1D children/adolescents was 45%. In addition, the proportion remains higher, which has important implications for adapting health and social care systems.

Vitamin D deficiency increases with age and adiposity in Emirati children and adolescents irrespective of type 1 diabetes mellitus: a case control study

BACKGROUND

Association of vitamin D (25(OH)D) deficiency with obesity and diabetes has been well-established in paediatric and adult populations. This study aims to report the association of 25(OH)D deficiency with body composition and prevalence of 25(OH)D deficiency in Emirati children and adolescents, who attended a diabetes centre in the United Arab Emirates.

METHODS

Using Abu Dhabi Diabetes and Obesity Study cohort, type 1 diabetes (T1D) and normoglycaemic (NG) participants between 4-19 years of age were selected. WHO criteria were used to define 25(OH)D cut-offs: deficient (< 30 nmol/L), insufficient (30-50 nmol/L) and sufficient (> 50 nmol/L). Based on CDC recommendations, BMI percentile was categorised as underweight, normal weight, overweight and obesity.

RESULTS

After age and sex matching, 148 T1D cases and 296 NG controls were identified. 25(OH)D deficiency was observed in 22.3% (n = 33) T1D and 40.5% (n = 120) NG participants. 25(OH)D levels were lower in adolescents (15 - 19 years) than children (4 - 7 years) in both T1D and NG groups (p = 0.018 vs p < 0.001). Females were more likely to be 25(OH)D deficient in both groups. Children and adolescents with BMI ≥ 95^th percentile were more likely to be 25(OH)D deficient than those with normal weight (OR: 2.69; 95% CI: 1.56, 4.64). Adiposity measures and 25(OH)D levels correlated negatively in both groups (T1D p < 0.01, NG p < 0.001).

CONCLUSION

Vitamin D 25(OH)D deficiency is notably prevalent in Emirati children and adolescents despite adequate sunlight throughout the year. The prevalence was lower in those with T1D which may be indicative of treatment compliance in this population. This study also confirms important negative association of serum 25(OH)D levels with body mass and obesity in this population.

Hubungan Paparan Sinar Matahari, Status Gizi, dan Asupan Makan terhadap Kadar Vitamin D Anak dan Remaja Penderita Diabetes Mellitus Tipe 1

Background: Previous research state the correlation between vitamin D deficiency and Type 1 diabetes. The deficiency of Vitamin D is caused by vitamin D intake, sunlight exposure, or nutritional status. Indonesia, as a tropical country, is close to the equator and receives sunlight all year long. Little research has been done on vitamin D levels in children and adolescents with Type 1 Diabetes in Indonesia.Objective: The study aims to determine the relationship among sunlight exposure, nutritional status, food intake, and vitamin D levels in children and adolescents with Type 1 Diabetes.Methods: The study design was cross-sectional with a sample size of 31 children and adolescents aged 5-19 years. Sunlight exposure data were collected using the Sun Exposure Questionnaire form, nutritional status o BMI/age data were using the WHO Anthro, food intake data were using the Semi-Quantitative Food Frequency Questioner, and vitamin D level data were using the ELISA method. Statistical analysis was conducted by using SPSS Version 21 with Pearson and Spearman correlation test.Results: All respondents showed vitamin D deficiency. Most respondents had low sunlight exposure and nutritional status in the normoweight category. The majority of respondents had good energy and protein intake, excess fat, low carbohydrates, and low vitamin D and calcium.Conclusion:There is a positive relationship between sunlight exposure and vitamin D level (p = 0.001, r = 0.627). However, there is no relationship among nutritional status, protein intake, fat, carbohydrates, vitamin D and calcium on the level of vitamin D (p = 0.409; p = 0.240; p = 0.311; p = 0.822; p = 0.231; 0.382).

Effect of Cholecalciferol therapy on serum FGF23 in vitamin D deficient patients: a randomized clinical trial

INTRODUCTION

Fibroblast growth factor-23 plays an important role in regulating systemic phosphate homeostasis, and vitamin D metabolism. However, the effect of Cholecalciferol therapy on FGF₂₃ serum level in patients with vitamin D deficiency has not been studied, yet.

MATERIALS AND METHODS

This is a double-blind, randomized clinical trial on 119 vitamin D deficient patients in 2016. Biochemical variables of treatment and placebo groups were analyzed after 12 weeks of 50,000 IU of Cholecalciferol vs. placebo therapy once a week, by SPSS18.

RESULTS

After Cholecalciferol therapy, delta of serum PTH in treatment group was less than the controls (P < 0.001). However, delta values of serum 25(OH)D₃, 1,25(OH)₂D₃ and FGF₂₃ in vitamin D treated group were more than the placebo-treated ones (P < 0.001, P = 0.002, and P = 0.04, respectively). Moreover, FGF₂₃ serum level in treatment group was associated with serum calcium (P = 0.005, r = -0.256), and serum 1,25(OH)₂D₃ (P < 0.001, r = 0.529).

CONCLUSIONS

We propose that in these patients 1,25(OH)₂D₃ has a positive association with serum FGF₂₃, and hypostasized that serum calcium might be a down regulator of serum FGF₂₃.

Bone mineral density in children with acute leukemia and its associated factors in Iran: a case-control study

Acute leukemia is the most common malignancy in children. We showed that low bone mass is prevalent among children with leukemia, especially in femur. Serum calcium, exercise, chemotherapy protocol, and radiotherapy are the main contributing factors. We suggest that early diagnosis and treatment of this problem could improve bone health in them.

INTRODUCTION

Acute leukemia is the most common malignancy in children and has been reported to be associated with low bone mass. Due to lack of sufficient data about the bone mineral density of children with leukemia in the Middle East, and inconsistencies between possible associated factors contributing to decreasing bone density in these children, we aimed to conduct a case-control study in Iran.

MATERIALS AND METHODS

This case-control study was conducted on 60 children with acute leukemia and 60 age- and sex-matched healthy controls. Anthropometric data, sun exposure, puberty, physical activity, and mineral biochemical parameters were assessed. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA). Data analysis was done by SPSS software v. 21.

RESULTS

Serum calcium was higher in the control group (P = 0.012) while serum phosphorous, alkaline phosphatase, and serum 25(OH)D₃ were higher in children with leukemia with P values of 0.04, 0.002, and 0.036, respectively. Sun exposure and physical activity were more in healthy controls (P values <0.001 and 0.003, respectively). Prevalence of vitamin D deficiency in case and control groups was 57.8 and 79.4 %, respectively. This prevalence was higher in healthy controls (P value = 0.007). Both lumbar and femoral neck bone mineral apparent density (BMAD) were higher in the control group (P value <0.001). Serum calcium, physical activity, and radiotherapy were the most relevant factors associated with lumbar BMAD. Femoral neck BMAD was associated with chemotherapy protocol.

CONCLUSION

Low bone mass for chronological age is prevalent among children with leukemia, especially in the femoral neck. Serum calcium, physical activity, chemotherapy protocol, and radiotherapy are the main contributing factors.